1. Field of the Invention
The present invention relates to a dust proofing shutter built-in adapter of an LC type optical connector which interconnect a pair of opposed LC type optical connector plugs.
2. Description of the Conventional Art
Conventionally, as shown in patent document 1 which is a prior application of the present patent application, an adapter for an optical connector has been proposed by the applicant of the present invention, the adapter for the optical connector being provided with a shutter plate which integrally has a support shaft in its lower end so as to close a fitting portion of the optical connector of the connector housing in a state of being arranged diagonally in the fitting portion, and rotatably bears protruding portions provided in both ends of the support shaft in a lower portion of the fitting portion of the optical connector of the connector housing, and a leaf spring which energizes the shutter plate in a closing direction, and being structured such that the shutter plate is opened against a pressing force of the leaf spring by fitting the optical connector to the fitting portion of the connector housing.
Further, as shown in patent document 2 and patent document 3 which are prior applications by the applicant of the present invention, there has been proposed by the applicant of the present invention an interconnecting adapter for LC type optical connectors which can achieve an improvement of a workability and a cost reduction on manufacturing, and can prevent a retaining capacity of an LC type optical connector plug from being lowered, by provision of a housing constructed by an integral structure which is open in both ends and can accept the LC type optical connector plug from both directions, for the purpose of interconnecting a pair of opposed LC type optical connector plugs.
In the meantime, the conventional adapter for the LC type optical connector is structured such that optical axes of the LC type optical connector plugs are aligned with each other, the LC type optical connector plugs being fitted into fitting ends in both ends of a housing. At this time, in a state in which the LC type optical connector is not fitted into one fitting end, when an optical part which is associated with the LC type optical connector plug connected to the other fitting end is under an operating state, a harmful laser beam, for example, having a power of about 5 mW is conducted to the one fitting end, and there is a risk that the laser beam seriously harms a body of a worker, particularly, eyes of the worker in a work for fitting the LC type optical connector plug into the one fitting end. Further, there has been a problem that a foreign material or a dust enters into an inner portion from the fitting end, whereby there is a risk of generation of defective connection.
Accordingly, the applicant of the present invention has proposed an LC type optical connector interconnecting adapter which is provided with the shutter plate according to the structure shown in the patent document 1 mentioned above in the connector housing shown in the patent document 2 and the patent document 3, so as to prevent the LC type optical connector plug from seriously harming a body of a worker, particularly, eyes of the worker in a work for fitting the LC type optical connector plug having various concavo-convex shapes, securely prevent a foreign material from entering into an inner side of a fitting end and securely prevent a defective connection caused by the foreign material intrusion.
In other words, the LC type optical connector interconnecting adapter is structured, as shown in FIG. 13, such that fitting portions A and B of LC type optical connector plugs P1 and P2 are respectively provided in both ends of a connector housing 101 so that optical axes are aligned, a sleeve holder 105 is arranged in an inner portion of the connector housing 101, the sleeve holder 105 installing and retaining each of ferrules 124 in leading end portions of the LC type optical connector plugs P1 and P2 which are inserted from the fitting portions A and B in both ends, a shutter plate 111 and a leaf spring 118 are arranged at least within the one fitting portion A of the connector housing 101, the shutter plate 111 closing the fitting portion A in a diagonally arranged state, and the leaf spring 118 energizing the shutter plate 111 in a closing direction, and the shutter plate 111 is opened against a pressing force of the leaf spring 118 by inserting the LC type optical connector plug P1 from the fitting portion A of the connector housing 1, and fitting the LC type optical connector plug P1 to the sleeve holder 105.